Upon its release, 8 Diagrams debuted at number 25 on the Billboard 200, and number 9 on the Top R&B/Hip-Hop Albums chart with 68,000 copies sold in the first week[1] It has sold 202,000 copies in the United States as of April 2014.[2] The album received generally favorable reviews from most music critics, and earned greater acclaim than the group's previous album Iron Flag, based on an aggregate score of 73/100 from Metacritic.

On Sunday, August 5, 2007, at the Virgin Festival in Baltimore, RZA announced that the release date for the album would be November 13, 2007, noting that this is the third anniversary of the death of Ol' Dirty Bastard. However, the date was delayed to December 11, 2007.[4]

In a released statement, group leader RZA commented on the need for the group's return, stating "This is the perfect time for us to come back; the stars are aligned. It's like when we first started with Steve. We put out real hip-hop at a time when it was turning into pop or R&B. We brought the focus back to the music in its rawest form, without studio polish or radio hooks.... People want something that gives them an adrenaline rush. We're here to supply that fix. How could hip-hop be dead if Wu-Tang is forever? We're here to revive the spirit and the economics and bring in a wave of energy that has lately dissipated".[5]

At the public premiere of Wu: The Story of the Wu-Tang in New York City, Cappadonna revealed that Wu-Tang had recorded between 40 and 50 songs for the record, of which around fourteen would make up 8 Diagrams. Prior to the album's release, Loud.com issued a free 8 Diagrams mixtape containing exclusive and unreleased tracks, including "Thug World", "Life Changes", "Stick Me for My Riches", and "Weak Spot".[6]

8 Diagrams featured the eight living original Wu-Tang Clan members, with previously recorded material from Ol' Dirty Bastard, as well as a tribute track titled "Life Changes." The album marked the official inclusion of long time Wu-Tang Clan affiliate Cappadonna as an official member.[7] Auxiliary member Streetlife also appears on the album.

Unlike Wu-Tang's previous albums, which used the "darker, sinister, and street-oriented, signature Wu sound", RZA utilized a more experimental, orchestral, and more universal choice of music production for the album.

Ghostface Killah and Raekwon stated in interviews that they weren't comfortable with the album's release as it did not contain the signature "Wu-Tang sound".[10][11][12] Raekwon planned
a follow-up group album entitled "Shaolin Vs. Wu-Tang" without input from RZA.[13] It was later announced in Vibe magazine, however, that Shaolin Vs. Wu-Tang would be Raekwon's fifth solo album, and that it would feature guest appearances from several other group members, with no contributions from RZA. In regards to the album's direction, Raekwon stated "RZA doesn’t have to be on every album. I wanted to give some other producers a chance. It’s not about beef. We can stand on our own."[14]

In a BBC Radio 1Xtra interview, Method Man stated that "Watch Your Mouth" would be the album's first single. However, it was rumored that the song's producer DJ Scratch was unable to get a sample clearance, which resulted in its omission on the final release of the album.

Upon its release, 8 Diagrams received generally positive reviews from most music critics. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream critics, the album received an average score of 73, based on 33 reviews, which indicates "generally favorable reviews".[27]USA Today's Steve Jones commended the group members' performances despite the absence of Ol’ Dirty Bastard, stating "the lyrical swords wielded by the nine surviving members are as razor-sharp as ever".[26]Rolling Stone writer Christian Hoard called it "a terrific mix of classic Clan grime and enough new tricks to justify Inspectah Deck's claim that 'Wu-Tang keep it fresh like Tupperware.'".[24] Marisa Brown of Allmusic praised RZA's production, writing that "It's beautifully, impeccably produced, from the soundtrack strings and horns, to the philosophical samples and guitars that are interspersed throughout ... it deepens and grows with every listen."[17] Brown elaborated on its production and perceived 8 Diagrams as a departure from previous RZA-produced Wu-Tang Clan work, stating:

[I]t does focus on melody and guitars and strings, but it is also lush and well-crafted and smart and addictive. Part of what's made RZA and the rest of the Clan thrive is their unpredictability and inventiveness, and so to create something expected would be counterintuitive to the group's ethos, and to what's made them so revered and respected across nations and genres and generations.[17]

— Marisa Brown

However, Entertainment Weekly's Neil Drumming commented that the album is "... a drab dilution of the Wu's signature sample-heavy, raucous sound."[20] Thomas Golianopolous of Spin viewed that "The beats are mostly to blame [...] skeletal, low-key tracks that rarely match the rappers' palpable energy".[25] Giving the album 2 out of 4 stars, Los Angeles Times called its arrangements "largely tepid" and wrote that several songs lack the rappers' "distinctive personalities".[28]Slant Magazine's Dave Hughes wrote that the album "fails to cohere into anything greater than the sum of its parts" and expressed a mixed response towards RZA's production, stating "when RZA isn't attempting to tone-deafly integrate other people's old sounds into his old sounds, he just sticks with his old sounds".[29] Kelefa Sanneh of The New York Times criticized the album's production as well, but complimented the performances of Ghostface Killah and Raekwon, stating that they "provide many of the album’s highlights."[21]

Dave Heaton of PopMatters wrote "Critics often use the word 'cinematic' to describe the Wu-Tang sound. That word has never been more appropriate than with 8 Diagrams. RZA taps into his Ghost Dog and Kill Bill experiences to create imaginary film music, moody would-be scores to Westerns, martial arts, sci-fi and gangster films."[23]Blender's Jonah Weiner commended RZA's production as well, stating "RZA has always been hip-hop’s reigning minimalist, but his work scoring Kill Bill, most recently, seems to have strengthened his ear for ambiance and texture."[18] Weiner also complimented Method Man's delivery and rhymes on the album, stating that he sounds "rejuvenated."[18]Pitchfork Media's Nate Patrin complimented the group members' lyricism.[22] Sam Richards of Uncut gave 8 Diagrams 4 out of 5 stars, and stated "RZA’s lurching beats and raw, spectral productions, peppered with kung-fu film samples, are back to their thrillingly weird best. RZA’s dictatorial rule has ostracised Ghost and Raekwon, but you can’t argue with the results. On record at least, Wu-Tang have made the comeback of the decade."[30]